Eight replicates of a bacterium to be tested were
introduced into each column, so the column numbers
delineated different materials. Data collection for a full
89 wells (96 minus the 7 empty ones in column A) required approximately 134 minutes, or about 90 seconds
per well. Video images of each well were also captured.
The FT-IR spectra for known examples of each class
of bacteria were collected. These were used to generate a
discrimination method based on assignment of spectra
to classes. As with any biological sample, there is considerable variation within the class, so region selection and
spectral processing are critical. The analysis defines the
characteristics of each class mathematically. Unknowns
are then assigned a Mahalanobis distance, representing
how like or unlike the unknown is to each class. An assignment is made to the closest class, with reporting of
nearest neighbor classes for comparison. The results are
then color-coded for visualization.